Some hybrid vehicles include an electrified powertrain comprising an electric motor that is powered by a battery system. Such hybrid vehicles include battery electric vehicles (BEV), plug-in hybrid electric vehicles (PHEV), and the like. These hybrid vehicles include battery management systems (BMS) configured to monitor the battery system. This monitoring typically includes estimating states of the battery system (state of charge (SOC), voltages, etc.) and parameters of the battery system (resistances, time constants, etc.).
These states and parameters are also utilized to determine other states/parameters, such as the state of power (SOP) of the battery system and/or the state of health (SOH) of the battery system. Linear models are often used for this state/parameter estimation, but these models are typically inaccurate. Non-linear models could be used instead, but these models are typically difficult to tune. Accordingly, while such BMS work for their intended purpose, there remains a need for improvement in the relevant art.